Abstract : The first part of the report deals with the searching of flare stars in the Pleiades and Praesepe clusters. 13 flares have been found on the Pleiades and 2 on the Praesepe. Position and characteristics of the flare stars are given. The second part deals with the study of the Orion Nebula with monochromatic liquid filters. The results are contained in the Supplement to the Monochromatic Atlas of the Orion Nebula of Wurm-Rosino and are here summarized. In the third part are given the spectral types of stars in or near the Orion Nebula derived by photographs taken with the objective prism applied to the Schmidt telescope of 40 cm. (Author)